Upper-pulling mechanism



NOV. 25 1924' E. A. HOLMGREN UPPER PULLING MECHANISM Original Filed Oct. 22 1919 nmmu M Z Patented Nov. 25, 1924,

UNITED STATES PATENT OFFICE.

ERIC A. HO'LMG-REN, OF LYNN, MASSACHUSETTS, ASSIGNOR TO UNITED SHOE MACHIN ERY CORPORATION, OF PATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

UPPER-PULLING I MECHANISM.

Original application filed October 22, 1919, Serial No. 332,520. Divided andthis application filed March 1 '0 all whom it may concern:

Be it known that I, EnIo A. HOLMGREN, a. citizen of the United States, residing at Lynn, in the county of Essex and State of Massachusetts, have invented certain Improvements in Upper-Pulling Mechanisms, of which the following description, in connection with the accompanying drawings, is a specification, like reference characters on the drawings indicating like parts in the several figures.

This invention relates to upper pulling mechanism, the present application being a division of my prior application for Letters Patent for improvements in machines for shaping uppers over lasts, Serial No. 332, 520, filed on October 22, 1919. The invention is herein illustrated in its application to gripper mechanism adapted for use to pull an upper at the toe or at the side of the forepart in pulling-over machines of the type shown in United States Letters Patent No. 1,029,387 granted on June 11, 1912 upon an application of R. F. McFeely. It will be recognized, however, that in various novel and useful aspects the invention is not limited to that type of machine but is generally applicable to various types of upper pulling machines.

A feature of the invention consists in a novel construction and arrangement of mechanism for controlling the force of the pull on the upper. One important object of the invention is to provide means whereby the uppers of different shoes, notwithstanding differences in the character of the upper materials and in the manner in which they may be seized by the gripper, will be pulled with sufficient for e to stretch them and shape them properly over their lasts, with insurance at the same time against danger of overstrain such as might tear the ma terials. This object is attained, in the construction shown, by the provision of novel gripper mechanism which is automatically ope "ative when the upper has been pulled with a predetern'iined degree of force'to maintain the pulling tension substantially constant irrespective of further relative pulling moven'ient between the gripper and the shoe, the illustrative construction comprising mechanism which is yieldable when Serial No. 544,915.

a definite pulling tension is exceeded to cause the gripper to relax its hold on the upper suficiently to permit the upper to slip in the gripper jaws and is then automatically operative as the tension is relieved to cause the upper to be gripped again with sufficient force to hold it from slipping. Under some conditions the gripper may thus operate with a succession of relaxing and gripping impulses to maintain the force of the pull substantially constant without overstraining of the upper materials during a portion of the relative pulling movement between the gripper and the shoe.

The above and other features of the invention, including also a novel construction and arrangement of mechanism for effecting relative opening and closing movements of gripper jaws, and various details of construction and combinations of parts, will now be described with reference to the accompanying drawings and pointed out in the claims.

In the drawings:

Fig. 1 shows in front elevation a gripper mechanism embodying the features of the present invention and arranged, for example, to pull an upper at the side of the forepart in a pulling over machine of the type above referred to, the parts being shown in starting position;

Fig. 2 is a view similar ,to' Fig. 1, showing the parts in the positions which they assume in pulling an upper; and

Fig. 3 is a view similar to Figs. 1 and 2, 1'1- lustrating the positions of the parts after the gripper has released theupper, the gripper being shown in its relation to tacker mechanism whereby the opening of the gripper jaws is effected.

The gripper mechanism shown comprises an operating member or bar 70 which is connected at its upperend to the usual gripper lever 2 and extends downwardly through and in sliding engagement with a block 72 guided for lateral liltYiCii'lQllt between opposite side portions of a guide bracket 74.- on the frame of the machine, one side portion only of the bracket being shown in the drawings. In addition to its lateral movement along the guideway of the bracket 74, the block 72 is permitted to move up- 86 of the gripper bar extends. At its lower vwardly and downwardly at times between the the block 72 .and nuts 82 on the bar 70 is mounted a spring 84 against the resistance of which the bar may be moved downwardly afterthe ears 8 0 engage the bracket 74. V

At its lower end the bar 70 is provided .with .a diametrically reduced portion 86 .upon which is slidingly mounted a gripper jaw carrier .88 having laterally extending ears 90 and 92 through which the lower part end the member 88 is constructed to provide agripper jaw 94 which for purposes of distinction may be referred to as a fixed jaw. Plvoted on the member 88 adjacent to the jaw 94 is a co-operating gripper aw 96 having a shank port-ion 98 extending on the opposite side of its pivot from its upper gripping portion, whereby movement of the jaw 96 relatively to the jaw 94 is controlled.

For the purpose of such control the shank 98 ofthe pivoted jaw is engaged on its upper and lower sides respectively by rolls 100 and 102 which are mounted 011 a controlling member or closing slide 104 having laterally extending. ears 106 and 108 which are slidable on the lower end portion of the part 86 of the gripper bar, these ears being disposed respectively on'opposite sides of the laterally extending ear 92 of the member 88. It will'be evident that, as the parts are thus constructed, a downward movement of the slide 104 relatively to the member 88, or an upward movement of this member relatively to the slide, serves by the action of the roll 100'on-the shank 98 of the gripper jaw 96 to swing this jaw toward the co-operating jaw 94 and thus to close it on the stock, while a reverse relative movement of the parts serves by the action of the roll 102 on the shank 98 to open the aws.

For positioning the gripper jaws normally lengthwise of the gripper bar a spring 110 is provided the lower end of which is in engagement with nuts 112 on the part 86 of the bar and the upper end of which presses against the ear of the member 88 to hold this ear normally in engagement with the lower end face of the larger upper portion of the gripper bar. In order to control the opening and closing movements of the jaw 96, the slide 104 is connected tothe upper end portion of the gripper bar 70 by toggle mechanism comprising a link 114 pivot-ally mounted oil-the ear 108 of the slide, a bell crank lever 1 16 mounted on a pivot 118 on the bar 70 with its lower arm arranged to serve as a toggle link, and an intermediate link 120 connecting the link 114 to the lower arm of the bell crank, the series of links thus comprising an upper toggle and a lower toggle. The other arm of the bell crank 116 isconnected to a pin 122, mounted in downwardly extending ears on the block 72, the arm being provided with a slot 124 through which the pin extends. A spring 126 connected to the ear 108 and to the link 114 acts on the link to hold it normally in engagement wit-h a stop pin 128 on the member 88.

By reference to Fig. 1 it will be seen that when the gripper is in upper receiving position the pivoted jaw 96 is held outwardly away from the jaw 94 by the action of the roll 102, the slide 104 being held upraised in relation to the ear 92 of the member 88 by the action of the toggle mechanism, the lower link 114 of this mechanism being held by the spring 126 against the pin 128 and the bell-crank member 116 being so disposed as to break the upper toggle and thus shorten the connection between. the upper enlarged end portion of the bar 70 and the slide 104. While the parts are thus disposed the operator presents the shoe to the ma- Chine and arranges the margin of the upper between the open gripper jaws. During the initial portion of the updraw movement of the lever 2 after the starting of the machine the spring 84 holds the block 72 with its pivot pin 122 in its lowermost positionas shown in Fig. 1, permitting the bar 70 to slide upwardly through the block and to raise the pivot 118 on which the bell crank 116 is mounted, thus swinging the bell-crank into the position illustrated in Fig. 2 and straightening the upper toggle. In the meantime the spring 110 in the upward movement of the lower portion 86 of the gripper bar serves to raise the member 88 and the gripper jaws, this upward movement of the jaws and the simultaneous downward movement of the slide 104 caused by the straightening of the toggle co-operating to close the pivoted jaw 96 quickly upon the stock through the wedging action of the roll on the shank of the pivoted jaw. After the jaws have thus been closed and the stock has been firmly gripped, the continued upward movement of the gripper bar serves to raise the block 72 and the gripper jaws while the latter grip the stock securely between them, the slide 104 being locked by the toggle mechanism in jaw closing position. If the force of the pull on the upper becomes sufiicient to overcome the force of the spring 110, the latter yields slightly and permits the gripper bar to inoverelatively to the member 88 and the gripper jaws.

Since the gripper bar isat this time rigidly connected to the slide 104 by the members 114, 116 and120, the bar in itsmovement relatively to the gripper aws pulls the slide 104 along with it and causes the lower roll 102 by its action on the shank 98 of the pivoted jaw to effect a slight movement of this jaw such as to cause it to relax its hold upon the upper suificiently to permit the upper to slip between the jaws. As the upper begins to slip, however, and the stress is relieved, the spring 110 immediately reacts to force the member 88 and the aws upwardly and thus cause the gripper again to establish a firm hold on the stock by reason of the wedging action of the roll 100. These operations may take place repeatedly during the latter portion of the pull of the gripper. It will thus be seen that the strength of the pull on the upper is not permitted to exceed substantially the force of the spring 110 and that irrespective ot' the character of the upper stock and the manner in which the margin of the upper may have been gripped initially by the jaws, insurance is afforded that the degree of tension applied to different uppers or to different portions of an upper will be substantially the same. The operator is permitted by adjustment of the nuts 112 to vary the stress of the spring 110 and thus to determine the force of the pull applied to the upper.

In order to cause the gripper to be opened as usual in the overdrawing operation to release the stock, the middle link 120 is provided with a projection 130 which is engaged by the usual tacker mechanism as the latter is swung inwardly toward the shoe. This causes the lower toggle to be flexed against the tension of the spring 126, as shown in Fig. 3, and raises the slide 104 to open the gripper. As the gripper, upon its release of the stock, springs inwardly and upwardly away from the tacker mechanism, the spring 126 swings the link 114 back against the pin 128, thus straightening the toggle and closing the jaws again. IVhen the gripper bar is moved downwardly in the return of. the parts to starting position, the ears on the block 72 are carried into engagement with the frame bracket 74 and limit downward movement of the block, causing the gripper bar in its continued downward movement to turn the bell-crank 116 into the position illustrated in Fig. 1, thereby flexing the upper toggle and reestablishing the open relation of the gripper jaws.

IVhile the invention is herein illustrated in its application to an organization in which the pulling of the upper is effected by movement oi the gripper, it will be recognized that in many of its novel and useful aspects the invention is applicable to an organization in which the pull is efi'ected by movement of the last relatively to the gripper.

Having described the invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between. them, and controlling means automatically operative through relative movement of said jaws in response to their pull on the upper to limit the force of the pull applied to the upper and then to maintain said force substantially constant during further relative pulling movement between the gripper and the shoe.

2. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between them, and means automatically operative in response to resistance of the up per when a definite pulling tension is exceeded to cause said jaws to relax their pressure on the upper and permit it to slip and then as the. tension is relieved toresume their effective hold upon the upper.

3. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between them, said jaws being bodily yieldable in response to resistance of the upper when a definite pulling tension is exceeded, and means automatically operative upon such yield of the jaws to cause them to relax their pressure on the upper and permit it to slip.

4. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between them, said jaws being bodily yieldable in response to resistance of the upper when a definite pulling tension is exceeded, and relatively unyieldable means arranged to act on one of the jaws in response to such yield to cause the jaws to relax their pressure on the upper and permit it to slip.

5. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between them, a device for controlling the relative movement of said jaws, and spring means against the resistance of which said controlling device and the aws are relative ly movable bodily in response to resistance of the upper as the upper is pulled, said controlling device being automatically operative in response to such relative movement to cause the jaws to relax their pressure on the upper and permit it to slip.

6. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between them, and controlling means includ ing a spring adjustable to a predetermined degree of stress and automatically operative in response to resistance of the work during the pull to cause the jaws to relax their grip and to slip on the upper when the stress of the spring is overcome for maintaining the force of the pull substantially constant.

7. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between them, a spring against the resistance of which said jaws are bodily yieldable in response to resistance of the upper as theupper is pulled, meansautomatically operative upon such yield cf the jaws to cause them to relax their pressure on the upper and permit it to slip, and means for adjustingthe tension of said spring to regulate the force of the pull applied to the upper.

8. In mechanism of the class described, an upper pulling gripper comprising jaws one of which is pivotally connected to the other for opening and closing movements, said pivoted jaw having a shank portion extended on the opposite side of its pivot from its upper gripping portion, means for engaging said shank portion to control the movement of said pivoted jaw relatively to the other jaw, and spring means against the resistance of which said jaws and controlling means are relatively movable in response to resistance of the upper as the upper is pulled, said controlling means be- 'ing arranged to act upon the pivoted jaw in response to such relative movement to cause the jaws to relax their pressure on the upper and permit it to slip.

- 9. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between them, and means for closing said jaws and for operating them to pull. the upper including mechanism automatically operative in response to resistance of the upper when a predetermined pulling tension is exceeded to cause the jaws to relax their pressure on the upper and permit it to slip and then to resume their effective holding pressure on the upper as the tension is relieved.

10. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between them, a member for impartingupper pulling movement to said jaws, and controlling means to cause said jaws to relax their etlective holding pressure on the upper when a predetermined degree of pulling tension is exceeded and permit the upper to slip in the jaws and to resume their effective hold on the upper before the ten sion is decreased substantially below the degree thus predetermined.

11. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between them, a member for imparting upper pulling movement to said jaws, a spring connection between said member and the aws arranged to yield in response to resistance of the upper, as the upper is pulled, and means,v

connected to said member for effecting relative movement of the aws in response to such yield to cause them to relax their pressure on the upper.

12. In mechanism of the class described, an upper pulling gripper comprising aws relatively movable to grip an upper between them, a member for imparting upper pulling movement to said aws, a spring connection between said. member and the jaws in such yield to cause the aws to relax their pressure on the upper.

13. In mechanism of the class described, an upper pulling gripper comprising a pair of jaws one of which is pivotally connected to the other for closing and opening movements, said pivoted jaw having an extended shank portion, a member for imparting upper pulling movement to'said jaws, a spring connection between said member and the jaws arranged to yield in response to resistance of the upper, a device arranged to engage the shank portion of said pivoted jaw for controlling closing and opening movements of said jaw, and means connecting said device to the gripper operating member to cause the device to act on the pivoted jaw in response to such yield for relaxing the pressure of the jaws on the upper.

14. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between them, a member for imparting upper pulling movement to said jaws, a spr ng connection between said member and the jaws arranged to yield in response to resistance of the upper, a device for controlling relative closing and opening movements of the jaws, and a toggle mechanism arranged to be straightened in the closing of the jaws and to be held substantiallystraight to effect an unyielding connection between said controlling device and the gripper operating member to cause said device to act in response to such yield to effect a relative opening movement of the jaws.

15. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between them, a gripper bar along which said jaws are slidingly movable, a spring against the resistance of which the jaws and the bar are relatively movable in response to resistance of the upper asthe upper is pulled,

a device also slidingly mounted on said bar for controlling relative closing and opening movements of the jaws, and means for controlling said device to render it eliective in such relative movement of the bar and the jaws to cause the jaws to relax their pressure on the upper.

16. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between them, a gripper bar along which said jaws are slidingly movable, a spring against the resistance of which the jaws and the bar are relatively movable in response to resistance of the upper as the upper is pulled, a device also slidingly mounted on said bar for controlling relative closing and opening movements of the jaws, and means connecting said device to the bar to render the device etlective in the relative movement of the bar and the jaws to cause the jaws to relax their pressure on the upper.

17. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between them, and means responsive to resistance of the work in the upper pulling operation for controlling the gripping pressure of said jaws upon the upper to cause said pressure to be successively relaxed and increased durin g the pull.

18. In mechanism of the class described, an upper pulling gripper comprising jaws relatively movable to grip an upper between them, an operating member movable in directions toward. and from said jaws, and a toggle arranged to be straightened by movement of said member away from the jaws to control the relation of the jaws to each other in pulling the upper.

19. In mechanism of an upper pulling gripper comprising jaws pivoted together and relatively movable to grip an upper between them, operating means comprising parts relatively movable for closing the jaws on the upper, and a toggle connection between said parts arranged to be straightened in the relative closing movement of the aws.

20. In mechanism of the class described, an upper pulling gripper comprising a pair of jaws one of which is pivotally connected to the other and is provided with an extended shank portion, operating means comprising parts relatively movable initially i'or closing the jaws on the upper and including a device arranged to act on said shank portion. of the pivoted jaw to close it, and a toggle mechanism connected to said device and arranged to be operated by the relative movement of said parts to effect closing movement of the pivoted jaw.

21. In mechanism of the class described, an upper pulling gripper comprising a pair of jaws one of which is pivotally connected the class described,

to the other and is provided with an extended shank portion, a gripper bar, a device slidingly mounted on said bar and arranged to toggle connection between said device and the gripper bar arranged to be straightened by movement of said bar inclosing the jaw.

In mechanism of the class described, an upper pulling gripper comprising a pair of jaws one of which is pivotally connected to the other for closing and opening movements and is provided with an extended shank portion, and controlling means comprising members for engaging said shank portion of the pivoted jaw on its opposite sides to impart to the jaw its closing and opening movements, said members being movable in a direction away from the upper to open the jaw.

28. In mechanism of the class described, an upper pulling gripper comprising jaws one of which is pivotally connected to the other and is provided with an extended shank portion, a bar on which said jaws are supported, and a controlling device slidingly mounted on said bar and having means for engaging said shank portion of the pivoted jawoii its opposite sides to impart to said j aiyits closing and opening movements by pressures directed toward and from the shoe respectively.

2 L In mechanism of the class described, aniupper pulling gripper comprising jaws relatively movable to grip an upper between thein, Ya'device for controlling relative clos and opening movements of said jaws, and means tor moving said aws bodily in onejdirection and said device in the opposite direction to effect the closing of the jaws.

In mechanism of the class described, an r pper pulling gripper comprising a pair of jaws one of which is pivotally connected to theother and provided with an extended shaifi'k portion, a controlling device arranged to engage said shank portion of the pivoted jawj'l'or imparting movement to said jaw,

operating means for moving said jaws in a direction to pull the upper, and means for simultaneously moving said device in the opposite direction to impart closing movement to said pivoted aw.

QQ/In mechanism of the class described, an ripper pulling gripper comprising a pair of jaws relatively movable to grip an upper between them, a gripper bar'movablegto operate the jaws for pulling the upper, a device movable lengthwise of said bar to effect relative closing and opening movements of the jaws, and a toggle connection between said bar and device arranged to be straightened by the initial pullingmoven'ient of the bar.

27;.{1111mechanism of the class described, an upper pulling gripper comprising a pair of jaws relatively movable to grip an upper between them, an operating member for moving said jaws to pull the upper, a jaw closing member, and connections between said members for moving the jaw closing member in the opposite direction from the operating member to grip the upper by the initial portion of the movement of said operating member and for then moving said jaw closing member in the same direction as the operating member in the upper pulling movement of the jaws.-

28. In mechanism of the class described, an upper pulling gripper comprising a pair of jaws relatively movable to grip an upper between them, an operating member movable in a direction away from the work to cause the jaws to pull the upper, a jaw closing member, and toggle mechanism arranged to be operated by the movement of said oper ating member away from the work to force the jaw closing member toward the work to close the jaws and then to hold the jaws closed during further movement of said operating member.

29. In mechanism of the class described,

an upper pulling'gripper comprising a pair of jaws relatively movable to grip an upper between them, a gripper bar for moving said jaws to pull the upper, a jaw closing slide, toggle connections between said gripper bar and slide, and means for operating said toggle connections by the operative movement of said gripper bar to render said slide effective to control the gripping of the upper by the jaws.

30. Inmechanism of the class described, an upper pulling gripper comprising a pair of jawsrelatively movable to grip an upper between them, an operating member for moving said jaws to pull the upper, a jaw closing member, toggle connections between said operating member and jaw closing memher, and a device relatively to which said operating member is initially movable, said device being arranged to act on said toggle connections in response to the movement of the operating member to force said jaw closing member toward the work to cause said jaws to grip the upper.

31. In mechanism of the class described, an upper pulling gripper comprising a pair of jaws relatively movable to grip an upper between them, an operating member movable in a direction away from the work to cause the jaws to pull the upper, a jaw closing member, toggle mechanism for controlling said jaw closing member, and a device responsive to movement of said operating member away from the work for straighten- I ing said toggle mechanism.

32. In mechanism of the class described, an upper pulling gripper comprising a pair of jaws relatively movable to grip an upper between them, an operating member for moving said jaws to pull the upper, a jaw I closing slide, a bell-crank carried by said operating member, connections between one of' the arms of said bell-crank and said closing slide, and a member arranged to act on the other arm of said bell-crank in response to movement of said operating member to move the closing slide into jaw closing position. I

' 33. In mechanism of the class described, an upper pulling gripper comprising a pair of jaws relatively movable to grip an upper between them, a gripper bar for moving said jaws to pull the upper, a jaw closing slide, toggle connections between said bar and slide including one arm of a bell-crank pivotally mounted on said bar, and a device ar ranged to act on the other arm of said bellcrank in response to movement of the gripper bar to cause said toggle connections to force the closing slide toward the work for closing the jaws on the upper.

34. In mechanism of the class described, an upper pulling gripper comprising a pair of jaws relatively movable to grip an upper between them, an operating member movable in a direction away from the work to cause said jaws to pull the upper, a jaw closing member, and connections between saidmem bers for effecting relative closing movement of the jaws in response to movement of said operating member, said connections including a toggle which is yieldable in response to pressure against it to cause said closing member to effect subsequently a relative opening movement of the jaws for releasing the upper.

35. In mechanism of the classldescribed,

an upper pulling gripper comprising a pair of jaws relatively movable to grip an upper between them, a gripper bar for movlng said jaws to pull the upper, a jaw closing slide, toggle connections between said bar and slide comprising opposite end links and an intermediate link affording a pair of toggles, means for imparting jaw closing movement to said slide by thejflexing of one of said toggles in response to movement of said operating member, and means for subsequently imparting opening movement to said slide by the flexing of the other toggle.

36. In mechanism of the class described, an upper pulling gripper comprising a pair of jaws relatively movable to grip an upper between them, a gripper bar for moving said jaws to pull the upper, a jaw closing slide, toggle connections between said bar and slide comprising opposite end links and tially stationary against swinging movement during jaw closing movement of the slide, said last named link being movable against the resistance of said spring to break the toggle connections for opening the aws to release the upper.

37. In mechanism of the class described, an upper pulling gripper comprising a pair of jaws relatively movable to grip an upper between them, an operating bar for moving said jaws to pull the upper, a jaw closing slide, and connections between said bar and slide comprising a series of three toggle links arranged to move said slide into jaw closing position in response to movement of said bar and to lock the slide in said position, a pair of said links being yieldable in response to pressure to unlocl: the closing slide and cause the jaws to release the upper.

In mechanism of the class described, an upper pulling gripper comprising a pair of jaws relatively movable to grip an upper between them, an operating member for moving said jaws to pull the upper, ajaw closing slide arranged to control relative opening and closing movements of the jaws, connections between said operating member and slide for moving said slide initially into jaw closing position and for maintaining it subsequently in such position during the pulling of the upper, and a yielding connection between the jaws and said op erating member to permit bodily yield of the jaws relatively to said closing slide in response to resistance of the upper to cause them to relax their grip on the upper under the control of the said slide.

39. In mechanism of the class described, an upper pulling gripper comprisingapair of aws relatively movable to grip an upper between them, an operating member for moving said jaws to pull the upper, a controlling member for effecting relative closing and opening movements of the jaws through relative movements between it and the jaws in respectively opposite directions, connections between said operating member and the jaws for moving the jaws with the operating member in the direction of pull, and mechanism automatically operative in response to the upper pulling movement of of said operating member to move said controlling member in the opposite direction for effecting a quick closing or" the jaws upon the upper.

In testimony whereof I have signed my name to this specification.

ERIC A. HOLMGR'EN. 

